Odontogenic keratocyst (OKC) rarely extends to the maxillary sinus and pterygoid process. However, residual or recurrent lesions occur more frequently in these sites than at other sites, and removal is often difficult. We experienced a case of recurrent OKC in the maxilla that extended to the maxillary sinus and pterygoid process and was removed via a Le Fort I osteotomy. A 59-year-old woman visited our hospital in August 2020 with the chief complaint of swelling in the posterior right maxilla. The patient had undergone a cystectomy at the age of 56 years, and a cystic lesion was found in the same area three years and two months after surgery, which was diagnosed as recurrent OKC. The lesion partially extended to the posterior sinus wall and the pterygoid process. A cystectomy was performed in September 2020 via a Le Fort I osteotomy. This approach provided a direct view of both the maxillary sinus and the pterygoid process, and the lesion could be removed. The pathological diagnosis was OKC. No recurrence was observed at two years and three months after surgery, and close follow-up is ongoing.
